1. Field of the Invention
The present invention relates to a sheet processing apparatus for executing a predetermined processing on a sheet on which an image is formed and an image forming apparatus provided with this sheet processing apparatus.
2. Description of the Related Art
In recent years, an electrophotographic type image forming apparatus for forming a high quality image such as silver halide photography has been developed. In such an image forming apparatus, a L-size (photographic size) smaller than postcard-size cannot be used. Thus, a conventional image forming apparatus has adopted a method in which a photographic image is imposed on the A4 size sheet and this sheet is cut into a predetermined dimension if the photographic size like the L size is desired as an output object. As a cutting device for cutting this sheet into a specified dimension, technology disclosed in Japanese Patent Application Laid-Open No. 10-76495 has been generally known. According to Japanese Patent Application Laid-Open No. 10-76495, an output object on which an image is recorded with an image forming apparatus or the like is placed on a supporting base plate of the cutting device off line and then cut into a predetermined dimension.
When an output object same as a certain output object of those created in the above-described manner is produced again, the color and density of the output object needs to substantially coincide with those of the output object created in advance. However, it is often difficult for an operator not skilled in image processing to output an image having the same quality as the preceding output object, thereby taking a long time for that processing, so that waste of material increases due to generation of unacceptable printed products.
To meet such a problem, a print system capable of outputting a print image having the same color and density as a previous output product has been proposed. For example, the print system disclosed in Japanese Patent Application Laid-Open No. 2000-10207 records image processing information indicating an image processing method applied to each image on the back surface of an output product when printing an input image such as an image taken with a digital camera or the like. Then, when creating a print having the same color and density as that output product, the image processing information of the output product to be reproduced again is read from the back surface of the output product and the same image processing is executed based on that information.
However, if the cutting device disclosed in Japanese Patent Application Laid-Open No. 10-76495 and the print system disclosed in Japanese Patent Application Laid-Open No. 2000-10207 are connected as an electrophotographic type image forming apparatus capable of cutting an output product and recording image processing information on the back surface of the output product, the size of the entire apparatus increases, which is a problem to be solved. Further, productivity the cutting device connected to the aforementioned print system becomes a considerably low because it cuts output products off line. Even if the cutting device is so constructed as to cut the output products on line, its productivity of printing is still low because the size of the apparatus is large. Further, the above-mentioned combination of the cutting device and apparatus induces a further drop in productivity because the output product needs to be stopped for each of both the cutting operation and the recording operation to the back surface of the product.